Abstract

This study investigated the effects of feedback on performance with pairs of isomorphic items that were embedded within consecutive mathematics web-based practice tests. Participants were randomly assigned to different experimental testing conditions: (1) feedback type: knowledge of correct response (KCR) or KCR with elaborated feedback (EF) in the form of additional explanations of the correct answer, (2) feedback timing: immediately after answering each item or delayed after completing the practice test, and (3) item format: multiple-choice or constructed response. The study specifically investigated the likelihood that participants would correctly answer the second version of the item, conditioned on their answer to the first version, across feedback type and timingconditions, and taking into account item format and participant initial ability. Results from 2445 participants showed a different pattern of results depending on initial item response correctness. With respect to feedback type, EF resulted in higher performance than KCR following incorrect first responses (suggesting initial lack of knowledge and understanding), but not following correct first responses. With respect to feedback timing, immediate feedback with additional delayed review resulted in higher performance than delayed feedback following incorrect first responses, but resulted in lower performance following correct first responses (immediate feedback without delayed review resulted in lower performance in both cases).